A wealth of research on the emergence of conduct problems (CP) has shown that young children who demonstrate elevated levels of CP in early childhood are at risk for persisting in problematic behavior across development (Broidy et al., 2003; Campbell, 2002). Numerous aspects of parenting have been linked to the emergence of CP, including positive dimensions such as warmth (Pettit, Bates, & Dodge, 1997) and negative dimensions such as rejection (Trentacosta & Shaw, 2008); therefore, it is not surprising that many widely implemented early interventions for CP target aspects of parenting (Lundahl, Risser, & Lovejoy, 2006; Reyno & McGrath, 2006). Although parenting interventions on the whole have been found to produce small to moderate effects in reducing CP (Lundahl et al., 2006; Piquero et al., 2009), they are not effective for all children (Webster-Stratton, 1990; Webster-Stratton & Hammond, 1997).Therefore, the investigation into moderators of effectiveness is of utmost importance to inform ways to refine interventions and to advance theory. Research has shown that one of the most robust predictors of parenting intervention effects is initial level of CP (Lundahl et al., 2006; Reyno & McGrath, 2006). Further, one of the most important aspects of motivation for change in parenting interventions is the parents' desire for behavioral change in their children (Nock & Kazdin, 2005). In the context of baseline child CP, parents might be less motivated to change or to engage in an intervention if a child's behavior is at a level that is tolerable, even if it is elevated compared to norms; only when behavior becomes more unmanageable would motivation increase to a great degree. The current study will examine children's initial level of CP as a moderator of the effectiveness of th Family Check-Up (FCU) parenting intervention. Further, in a moderated mediation framework, the current study will examine whether children's initial level of CP moderates the mediational pathways through which the FCU has been shown to be effective - through improving parenting and parental depression - to determine if the strength of the mediated effect changes as initial level of CP changes. It is hypothesized that improvements in CP and mediational pathways through which the FCU influences CP will be greater for children with higher initial levels of CP. The proposed training program includes formal coursework in advanced analytic techniques, directed readings on specific areas of research, and collaboration with experts in the fields of quantitative methods, clinical and developmental psychology, and public policy. This work is intended to address the NIMH strategic objective of developing new and better interventions to incorporate the diverse needs of individuals with CP and the objective of charting trajectories of mental illnesses by use of trajectory modeling to examine differences in the course of CP in high-risk children in the intervention and control groups. Findings from the proposed research will aid researchers in further understanding differential responsiveness to parenting interventions and refining interventions to best address the needs of children with CP.